Warren, MI 48397 Frost Dates
When can you plant in Warren, MI?
Typically, the last spring freeze lands around 04/21, roughly 236 days out. The first fall frost typically arrives around 10/31, about 190 frost-free days later.
Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Warren, not a forecast for this year.
What to do before the first frost
About 9 weeks of growing season left in Warren before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/21 isn't a guarantee
04/21 is the middle of 30 years of NOAA records, not a promise. Plant by 04/07 and you're betting against frost in roughly 9 years out of 10. 05/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Warren compares
At roughly 190 frost-free days, Warren places 20,968 of 40,283 ZIP codes in this dataset. Within MI, it ranks 19 of 1,153.
Learn more
local microclimates covers what one yard in Warren can differ from the 48397 normal. zone vs. frost date covers why Zone 6b and Warren's frost date answer different questions.